Healthline: What we know about breakthrough monkeypox cases
UC expert says people with certain medical conditions may be less likely to be protected
The World Health Organization announced recently that breakthrough infections have been reported in people who had been vaccinated against monkeypox. Healthline reported there is limited data available on the efficacy of the JYNNEOS shot, so it will take time to understand how effective it is at preventing infection. Data from the 1980s has shown that the vaccine was at least 85% effective, however, some health experts expect that number to change in the current outbreak. One of the experts cited in the Healthline story was Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the UC College of Medicine.
Carl Fichtenbaum, MD, of the Division of Infectious Diseases at the UC College of Medicine/Photo/Joe Fuqua II/UC Marketing + Brand
Fichtenbaum says that the vaccine has not been tested in humans to a large extent, so 85% is really a ballpark estimate.
Healthline reported the strength of people’s immune systems varies and certain individuals may not mount a strong enough immune response to avoid getting sick even if they are fully immunized.
“As always, those with immunosuppression, cancer, transplant patients, and persons with HIV who have a lower CD4+ lymphocyte count below 350 cells/mm3 would be more likely to not respond as well to vaccine and have a breakthrough infection,” Fichtenbaum said.
People older than 60 are also likely to be less protected, Fichtenbaum added.
Fichtenbaum says we are still learning about how common breakthrough infections are, and we don’t have the best track record for preventing the spread of infectious diseases during public health emergencies.
“Time will tell how many breakthroughs occur,” Fichtenbaum said.
Next Lives Here
The University of Cincinnati is classified as a Research 1 institution by the Carnegie Commission and is ranked in the National Science Foundation's Top-35 public research universities. UC's graduate students and faculty investigate problems and innovate solutions with real-world impact. Next Lives Here.
Related Stories
Cincinnati sees record rainfall in weekend deluge
July 21, 2026
The Cincinnati Enquirer talks to UC College of Engineering and Applied Science Associate Professor Patrick Ray for context about a July 17 rainstorm that dumped a record amount of rain on parts of Cincinnati.
Putting preschool into perspective
July 20, 2026
Preschool and childcare can be difficult to navigate for parents, as Spectrum News 1 Ohio recently reported. Waitlists are long, and factors like cost, location and transportation can limit options. According to a recent study published by The Annie E. Casey Foundation, only 41% of 3- to 4-year-olds in Ohio were enrolled in preschool between 2020 and 2024 — a 4% decrease from pre-pandemic numbers. For University of Cincinnati early childhood education faculty member Chad Nunamaker, that statistic has caveats.
Ticks that survive pesticides can withstand colder winters
July 17, 2026
Ticks that survive less-than-lethal doses of pesticide are able to withstand dangerous cold, which could help them expand their range farther north, according to researchers at the University of Cincinnati and the U.S. Department of Agriculture.